The fate of 7[14C]-methylguanine after administration to the rat.
1. To assess the significance of the methylation of nucleic acids known to be caused by certain carcinogens, the metabolic fate of 7[(14)C]-methylguanine was studied, with special reference to its possible incorporation into RNA and DNA. 2. The major part (approx. 95%) of the dose was excreted unchanged in the urine. A small amount of N-demethylation took place, as evidenced by the formation of radioactive adenine and guanine, and expiration of (14)C-labelled carbon dioxide. No evidence was obtained for the direct incorporation of 7-methylguanine into systems synthesizing nucleic acids, i.e. RNA in liver, DNA in intestine or in the foetus.
D000818:Animals; D002247:Carbon Isotopes; D002852:Chromatography, Ion Exchange; D004247:DNA / Q000096:biosynthesis*; D005260:Female; D005333:Fetus / Q000378:metabolism; D005753:Gastric Mucosa / Q000378:metabolism; D006147:Guanine; D007420:Intestine, Large / Q000378:metabolism; D007421:Intestine, Small / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000032:analysis / Q000378:metabolism; D008168:Lung / Q000378:metabolism; D008745:Methylation; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D011687:Purines / Q000032:analysis / Q000378:metabolism*; D012313:RNA / Q000096:biosynthesis*; D051381:Rats
D002247:Carbon Isotopes; D011687:Purines; D006147:Guanine; D012313:RNA; D004247:DNA